Current Sensor Handles Sub-5A Apps

Allegro MicroSystems, introduces its first fully integrated, giant magneto-resistive (GMR) based current sensor IC with ultra-high sensitivity for applications that require less than 5A current sensing. The IC incorporates GMR technology that is 25 times more sensitive than traditional Hall-effect sensor ICs to sense the magnetic field generated by the current flowing through the low resistance, integrated primary conductor.


The device senses very small currents with 1 mA resolution, exhibits a series resistance of 1 mΩ, and its QFN package measures 3 mm x 3 mm. Applications include handheld and laptop adaptor chargers, radios and walkie talkies, IoT load detection, small surveillance, and other motor control applications.

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The analog output provides a low-noise high-speed signal, which is proportional to the current flowing through the primary conductor. The full-scale bandwidth is 1 MHz and the response time of the device is typically 535 ns. The ACS70331 is offered in four factory-programmed sensitivity and offset levels to optimize performance over the desired current measurement range. The differential configuration of the GMR elements, relative to the integrated current conductor, provides significant rejection of stray magnetic fields, resulting in stable operation even in magnetically noisy environments.


Allegro’s ACS70331 current sensor IC operates from a single 3.3 V power supply and is qualified over the full commercial temperature range of –40°C to +85°C. Pricing is $0.53 each/1,000. Starved for more information? Then download a copy of the ACS70331 datasheet.


Allegro MicroSystems

Worcester, MA


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